Reproduction and development are highly integrated, hormonally dependent processes that can be acutely sensitive to chemical insult. Several halogenated polycyclic aromatic hydrocarbons, which are common Superfund contaminants, exhibit agonist as well as antagonist hormonal activity and are therefore potential reproductive and developmental toxicants. This project is composed of three subprojects. Each subproject has a different approach to the study of reproductive toxicity, yet the subprojects share the overall objectives of (1) characterizing the effects of selected halogenated polycyclic aromatic hydrocarbons on reproduction and development, (2) investigating the mechanisms that initiate and mediate the chemical-induced alterations in reproduction and development, (3) assessing possible health risks arising from exposure to these chemicals. This Subproject will assess PCB effects on various reproductive functions in order to identify and investigate mechanisms of processes sensitive to PCB insult. Specifically, the effects of PCBs on in vitro fertilization will be determined, and PCB effects on sperm motility, sperm capacitation, the acrosome reaction and fertilizing ability will be assessed in studies of mechanisms of adverse effects on in vitro fertilization. In vivo experiments will assess developmental toxicity resulting from exposure during mid-embryogenesis (gestation days 5 to 15) in the mouse, and in vitro embryo culture systems will be used to study adverse effects on early embryogenesis. Also, PCB effects on sexual behavior and areas of the CNS involved in gonadotropin secretion will be evaluated.